1. Field of the Invention
The present disclosure relates to method of preparing an iodine seed for treating eye disease or cancer, and an iodine seed prepared thereby.
2. Description of the Related Art
The prostate is an organ found only in men that makes a portion of semen and is an organ located below the bladder and near rectum. Prostate cancer is a malignant tumor that originates in the prostate gland, is one of the most common cancer types in males in the West, and is also the fastest growing cancer in males due to the effects of recent dietary habits in South Korea, which mostly develops in seniors over 50 years old. In developed regions such as North America and Western Europe, prostate cancer is the most common cancer accounting for about 20% of cancers among men, in which the frequency is the highest among cancers in males developed per year in the United States and prostate cancer is ranked second among causes of death due to cancer following lung cancer. With respect to South Korea, the frequency of prostate cancer also have been significantly increased in recent years as patients seeking hospitals have been increased due to an increase in life expectancy, an increase in seniors, westernization of dietary patterns, development of diagnostic techniques, and an increased awareness of prostate cancer. According to “Korea Central Cancer Registry Database” reported annually from the Korea Central Cancer Registry and Ministry of Health and Welfare, a proportion of prostate cancer incidence was 2.7% of cancers in males in 2001 and was ranked sixth at 3.0% in 2002, and since it has been most rapidly increased in recent years, it is expected that the incidence rate of prostate cancer will be further increased in the future. It is known that prostate cancer may be also developed due to hormone, dietary habits, and chemicals, in addition to a genetic predisposition.
Treatment methods of prostate cancer may include radical prostatectomy, irradiation, chemotherapy, or hormone therapy. Among these methods, radiation therapy using radiation is a method of treating cancer by using radioactive elements emitting gamma ray able to treat cancer, and the radiation therapy may be classified as external radiation therapy, in which cancer cells may be necrosed by external irradiation, and internal radiation therapy, in which a material emitting radiation, i.e., a radioactive magnetic fluid, is prepared and then introduced into the body, and a magnetic field is externally applied to allow radiation to be emitted to treat cancer.
I-125 has been generally used in the radiation therapy of prostate cancer. I-125 has a half-life of 59.4 days, and emits 27 key and 31 keV X-rays, and a 35 key gamma ray through an internal conversion process. The main application scope of I-125 is for medical use, and I-125 is used as an in vitro diagnostic reagent in radioimmunoassay and is also used as a source for treating eye disease and prostate cancer by being formed as a radioactive source in the form or a sealed source.
An I-125 seed has a structure in which I-125 is adsorbed on a silver (Ag) support (0.5 mm×3 mm) and a titanium tube (0.8 mm×4.5 mm) surrounds the silver support. The seed having the foregoing structure is directly inserted into the human body to treat cancer cells on internal tissues, and since the seed has low activity, the seed may be permanently left in biological tissues.
In relation to the iodine seed in which I-125 is adsorbed on silver support, “3M Brand I-125” commercialized by Lawrence Soft Ray Inc. has been commercially available as an actual iodine seed, and although “Best iodine-125” is commercially available from Best International, Inc., limitations in the preparation efficiency thereof have been pointed out so far.
With regard to the preparation of an iodine seed, a method of introducing an iodine by using electrochemical method (Non-Patent Literature 1), a method of adsorbing iodine after coating palladium (Pd) (Non-Patent Literatures 2 and 3), and a method of substituting iodine after forming an intermediate having chlorine anions (Cl−) introduced thereinto using solubility difference (Patent Document 1 and Non-Patent Literature 4) are known to date.
However, since these methods may require complicated procedures and may have low substitution efficiency of iodine, the methods may have limitations in commercializing an iodine seed. Accordingly, during research into a method of effectively substituting I-125 onto a silver support, the present inventors confirm that phosphates, oxalates, and arsenates are effective as an intermediate for preparing an iodine seed, thereby leading to completion of the present invention.